Objective To get more detailed information about the microsurgery of the Willis circle,in order to provide evidence of clinical operation.Methods The microsurgical anatomy of the Willis circle via combined frontotemporal-orbitozygomatic approach was studied in 5 adult cadaver brains under microsurgical scope. Results The Willis circle was composed of anterior communicating artery (ACOA), A 1 segments of the right and left anterior cerebral arteries (ACA), right and left internal carotid arteries(ICA) right and left, posterior communicating artery (PCOA), Pi segments of the right and left posterior cerebral arteries (PCA).The variation are present obviously in A 1 segment of the ACA. The outer diameter of left A 1 segment are larger than that of right ones. There are many perforating arteries of each part of Willis circle. Most of them arise from their original arteries, then course medial-superiorly to the optic tract, the pituitary stalk, the optic chiasm, the thalamus, hypothalamus, the floor of third ventricle, basal nuclei and internal capsule etc blood supplied areas. Conclusion To understand the microsurgical anotamy of the Willis circle and protections against its penetrating branches perfectly are the key to gain a good curative effect during the concerned operation .